March 2020 - AMSAT-BB - mailman.amsat.org

Where best to purchase LMR-240UF in the US?
by Hans BX2ABT 06 Mar '20

06 Mar '20

As in title. Need some 200 feet. Mail order is fine, delivery in Houston. Will be hand delivered to me in Taiwan, because I can't get the stuff locally. Cheers --Hans

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Re: [amsat-bb] sequencer
by MICHAEL WILLIAMS 06 Mar '20

06 Mar '20

Check out W1GHZ's "A Simple, Yet Fool-Resistant Sequencer" at http://www.w1ghz.org/small_proj/Simple_yet_Fool-Resistant_Sequencer_Rev_B.p… GL, K9QHO

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ANS-065 AMSAT News Service Special Bulletin - AMSAT Academy to be Held Prior to Dayton Hamvention
by Paul Stoetzer 05 Mar '20

05 Mar '20

AMSAT NEWS SERVICE SPECIAL BULLETIN ANS-065 The AMSAT News Service bulletins are a free, weekly news and infor- mation service of AMSAT North America, The Radio Amateur Satellite Corporation. ANS publishes news related to Amateur Radio in Space including reports on the activities of a worldwide group of Amateur Radio operators who share an active interest in designing, building, launching and communicating through analog and digital Amateur Radio satellites. The news feed on http://www.amsat.org publishes news of Amateur Radio in Space as soon as our volunteers can post it. Please send any amateur satellite news or reports to: ans-editor at amsat.org. You can sign up for free e-mail delivery of the AMSAT News Service Bulletins via the ANS List; to join this list see: http://www.amsat.org/mailman/listinfo/ans In this edition: * AMSAT Academy to be Held Prior to Dayton Hamvention SB SAT @ AMSAT $ANS-065 ANS-065 AMSAT News Service Special Bulletin AMSAT News Service Bulletin 065.01 From AMSAT HQ KENSINGTON, MD. DATE March 5, 2020 To All RADIO AMATEURS BID: $ANS-065.01 Come join us the day before Hamvention, for AMSAT® Academy – a unique opportunity to learn all about amateur radio in space and working FM, linear transponder, and digital satellites currently in orbit. AMSAT® Academy will be held Thursday, May 14, 2020, from 9:00am to 5:00pm, at the Dayton Amateur Radio Association (DARA) Clubhouse, loc- ated at 6619 Bellefontaine Rd, Dayton, Ohio. The $85 registration fee includes: • Full day of instruction, designed for both beginners and advanced amateur radio satellite operators, and taught by some of the most accomplished AMSAT operators. • Digital copy of Getting Started with Amateur Satellites, 2020 Edi- tion ($15 value) • One-Year, AMSAT® Basic Membership ($44 value) • Pizza Buffet Lunch • Invitation to the Thursday night AMSAT® get together at Ticket Pub and Eatery in Fairborn. Registration closes May 8, 2020. No sign ups at the door. No refunds, no cancellations. Registrations may be purchased on the AMSAT store at https://www.amsat.org/product/2020-amsat-academy-registration/ [ANS thanks Robert Bankston, KE4AL, Vice President - User Services for the above information] /EX In addition to regular membership, AMSAT offers membership in the President's Club. Members of the President's Club, as sustaining donors to AMSAT Project Funds, will be eligible to receive addi- tional benefits. Application forms are available from the AMSAT Office. 73 and Remember to help Keep Amateur Radio in Space, This week's ANS Contributing Editor, Paul Stoetzer, N8HM n8hm at amsat dot org

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Re: [amsat-bb] XW-2D Returns to Life!
by Hasan al-Basri 05 Mar '20

05 Mar '20

Hi George, (and anyone else who is interested in an easy way to evaluate your satellite rx performance) These remarks are with respective to linear birds, not FM Some of the satellite ops I work with run various SDRs (software defined radios like the FunCube Pro+). The software we use with them is called SDR Console v3 (Google SDR Radio or look at this group: main(a)sdr-radio.groups.io) What we do so we can compare apples to apples is the following: The software is designed to be able to measure relative signal levels at high accuracy (-dBM) 1. Connect a 50 ohm resistor to the antenna or preamp input. 2. Set the rx for maximum sensitivity (RF Gain) 3. Adjust IF Gain so that the 50 Ohm resistor produces a signal level of -95 dBM 4. This creates a common noise floor level calibration point so that we can compare local noise (environmental) as well as satellite signal levels. 5. Now disconnect 50 ohm resistor and change to "real" satellite antenna. Observe the increase in noise floor. If there isn't one, you have poor rx sensitivity. If there is an increase and it is 6 dB or more, you have local noise problems (environmental). If there is a small increase in noise, you likely have relatively low noise, and at least it exceeds the internally generated noise of your radio/preamp combo. Now, when we observe signals from the satellites, we can directly compare peak signal strength in dBm between our satellite setups. This includes, antenna polarity, antenna gain, feedline losses, differences in uplink power, differences in receiver noise figure, and locally generated noise like power line, WiFi hash, etc. All...easily and accurately done by having software that works correctly and a simple SDR Dongle using Simon's (G3ELI) software (which is free). For example: If KB7IJ has a noise floor of -76 and I have a noise floor of -90 (dBm), and he has a peak BEACON signal strength of -53 and I have a peak strength of --60, we can see two things; (these are real and typical measurements, btw) 1. His ambient noise is 14 dB higher than mine. He lives south of Dallas, Tx, and has to shoot thru the city to see sats. Lots of environmental noise! I live in rural Iowa. Much quieter. 2. His rx system has 7 dB greater gain than mine (antennas). That makes sense as he has 2x7 EL yagis and I have a single 5 EL Yagi. So all else being equal (and it almost never is), he should always see the birds 7 dB louder than I do (actual signal level, not SNR) Now look at SNR (Signal to Noise Ratio):...a much different story. How well do we hear the birds? His SNR (best): -76 dBm noise floor - (-53) signal = 23 dB SNR (signal is 23 above noise, loud!) My SNR (best ): -90 dBm noise floor - (-60) signal = 30 dB SNR So when we are both getting a satellite at our best signal level, I am hearing the bird 7 dB better than he is, even though his rx antennas are much better. Look what happens when the ssb signal is much weaker: If I am seeing the SSB signal at an SNR of 10 dB (the lowest signal strength that an SSB signal can be understood at): He is seeing it at only 3 dB SNR which is unreadable. In general, I nearly always hear both him and myself way better than he does, because my noise floor is so much better than his. Keep in mind, these are all RELATIVE measurements not ABSOLUTE. They are not meant to be lab grade, they are meant to be able to understand and measure reasonably well, how a satellite station is performing in the real world. Common calibration between stations allows us to compare how our systems are working. It's not perfect, but it is useful. (There are other factors, like the practical limit of SNR from any bird based on passband noise). If you can consistently see/hear passband noise, you are good. If you only hear it now and then, your rx system needs work) p.s. The software from Simon, also allows us to make MP4 recording (video and audio) of our satellite qsos, which can demonstrate some of the very dramatic ways to improve or ruin your ability to use satellites efficiently. That is to say, receive properly and not overdrive the satellite with excessive uplink power, because you can't hear worth a darn and don't know it. (Just continue to increase transmit power so you can hear yourself, taking more than your share of what is available, because it is a shared resource). I have hours or recordings of assorted stations doing exactly this (running excessive uplink power and thus producing downlink signals 6 dB or more louder than the CW beacon) and therefore stealing the available downlink power of others, driving them down into the noise floor. It's embarrassing. *The rule is simple: you should NEVER be louder than the CW beacon, period.* 73, N0AN Hasan On Wed, Mar 4, 2020 at 7:48 PM George Sakai <grsakai5120(a)yahoo.com> wrote: > Thanks for the info Hasan. What do you use to measure signal levels in > dBm? > > George N3GS > > On Wednesday, March 4, 2020, 03:43:43 PM CST, Hasan al-Basri via AMSAT-BB < > amsat-bb(a)amsat.org> wrote: > > > K7VNE reported to me this morning that he had been on XW-2D (long since > non-operational) and sigs were very good, but no one else was on. > > Signals were of good quality, no FM'ing of my SSB signal. > > I just checked it and had a pass of Max EL 2 deg to my East. It is there, > it is loud. *The CW beacon is raspy*. > > The passband was normal level and my signal was typical: > > Max Sig: -64 dBm > Noise Floor: -81 dBM > > I made an mp4 recording of the pass, with me calling CQ and announcing > Elevation and signal levels. > > https://drive.google.com/open?id=1lKYvARp4SyHUraAX9u6HQRbmnCiamJAM > > Download this mp4 file and play it back on any device (even a phone) and > you will see and hear what I did. > > I have seen no announcement about not using the satellite, but will watch > for same. > 73, N0AN > Hasan > _______________________________________________ > Sent via AMSAT-BB(a)amsat.org. AMSAT-NA makes this open forum available > to all interested persons worldwide without requiring membership. Opinions > expressed > are solely those of the author, and do not reflect the official views of > AMSAT-NA. > Not an AMSAT-NA member? Join now to support the amateur satellite program! > Subscription settings: https://www.amsat.org/mailman/listinfo/amsat-bb >

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APRSdroid
by Steve Kristoff 05 Mar '20

05 Mar '20

Those of you who said that APRSdroid works were right. I'm not the sharpest knife in the drawer, but I got it working without much fuss. I just confirmed on AISAT-1 that it works on my phone hooked up to my HT. So, I agree, don't believe all the bad reviews you see on the app Play Store. Steve AI9IN

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Wide or Narrow?
by Steve Kristoff 05 Mar '20

05 Mar '20

When aiming at the APRS satellites (ISS, AISat, any others?) should I use Wide or Narrow FM? I vaguely recall reading that narrow is good, but I can't find the reference. Your assistance is appreciated! Steve AI9IN

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Fwd: [Nouvel article] Rencontre Spatial Radioamateur 7 & 8 mars 2020 – Dernier jour pour vous inscrire !
by christophe.mcr 05 Mar '20

05 Mar '20

Nouvel article sur *AMSAT Francophone* <http://site.amsat-f.org/?author=2> Rencontre Spatial Radioamateur 7 & 8 mars 2020 – Dernier jour pour vous inscrire ! <http://site.amsat-f.org/2020/03/04/rencontre-spatial-radioamateur-7-8-mars-…> par Xtophe <http://site.amsat-f.org/?author=2> <http://site.amsat-f.org/wp-content/uploads/2020/02/RSRtitre.jpg> La cloture des inscriptions aux journées sera faite le *5 mars 2020 à 14h*. Elle nous permettra de mettre en place la logistique nécessaire notamment pour les Il ne reste que quelques places disponibles. La capacité du lieu ou se situe l'événement est limitée. *Pour réserver vos places, utilisez le lien ci dessous : * https://www.billetweb.fr/troisieme-rencontre-spatial-radioamateur *Xtophe <http://site.amsat-f.org/?author=2>* | 4 mars 2020 à 10 h 33 min | U

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XW-2D Returns to Life!
by Hasan al-Basri 05 Mar '20

05 Mar '20

K7VNE reported to me this morning that he had been on XW-2D (long since non-operational) and sigs were very good, but no one else was on. Signals were of good quality, no FM'ing of my SSB signal. I just checked it and had a pass of Max EL 2 deg to my East. It is there, it is loud. *The CW beacon is raspy*. The passband was normal level and my signal was typical: Max Sig: -64 dBm Noise Floor: -81 dBM I made an mp4 recording of the pass, with me calling CQ and announcing Elevation and signal levels. https://drive.google.com/open?id=1lKYvARp4SyHUraAX9u6HQRbmnCiamJAM Download this mp4 file and play it back on any device (even a phone) and you will see and hear what I did. I have seen no announcement about not using the satellite, but will watch for same. 73, N0AN Hasan

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VJB Cheap Yagis
by Joe 04 Mar '20

04 Mar '20

The awesome little "Cheap Yagis" https://www.wa5vjb.com/yagi-pdf/cheapyagi.pdf Has anyone modified the 144 Mhz one up higher in the band for Sat work, AND has anyone taken the VHF and the UHF versions and put them on a single hand held boom? Elements in line or at right angles? Joe WB9SBD

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AMSAT @ ScienceCity in Tucson AZ (14-15 March 2020)
by Patrick STODDARD (WD9EWK/VA7EWK) 03 Mar '20

03 Mar '20

Hi! AMSAT will be supporting the University of Arizona's K7UAZ radio club during the ScienceCity science fair on 14-15 March 2020 (a Saturday and Sunday). ScienceCity will be on the University of Arizona campus in Tucson, Arizona. This science fair is supported by several organizations at the university, and runs in conjunction with the Tucson Festival of Books that will also take place that weekend. More information about ScienceCity is available at: http://sciencecity.arizona.edu/ Information about the K7UAZ radio club is available at: http://k7uaz.com/ The K7UAZ radio club will have a booth in the "Science of Everyday Life" area at ScienceCity. This booth will showcase different facets of amateur radio, including amateur satellites. WD9EWK, and possibly other call signs, should be heard during demonstrations of satellite operating taking place at ScienceCity. If you hear us, please call and be a part of the demonstrations. The University of Arizona campus is in grid DM42, in Arizona's Pima County. QSLing will be determined by the call sign used for QSOs. For WD9EWK, I will upload my log to Logbook of the World, and will be happy to send QSL cards on request (please e-mail me the QSO details - no card or SASE is required to get my card). K7UAZ will confirm QSOs by QSL card, following instructions posted on QRZ.com. During the weekend, I will use my @WD9EWK Twitter account to post updates from ScienceCity. If you do not use Twitter, you can view these updates in a web browser without having a Twitter account at: http://twitter.com/WD9EWK Thanks, and 73! Patrick WD9EWK/VA7EWK http://www.wd9ewk.net/ Twitter: @WD9EWK or http://twitter.com/WD9EWK

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